Feed screw



Patented Mar, 12, 1929 N TED STATES PATENT :oFFic GUSTAF SIGURD BRANTINGSON, or GRAND HAVEN,MICHIGANQASSIGNOR T0 WILLIAM H. KELLER, me, or GRAND HAVEN, MIC GAN, A CORPORATION or MICHIGAN.

FEED scnnvv.

Application filed March 18, 1926. Serial ivql 95,699.

This invention relates to feed screws' and particularly to telescopic feed screws 1 for pneumatic drills. 1

One object of this invention isto provide a telescopic feed screw which will have a more rapid and more positive action than has heretofore been obtained in devices of this type. I f

Another object is to provide a feed screw which will. be strengthened throughout'its operating range without incorporating un necessarybulk and weight in the various parts comprising the device.

Other objects and advantages of my invention will become apparent in the following descriptio. w f In Figurel of the accompanying drawings is shown a cross section of'my telescopic feed screw installed in the casing of; a pneumatic drill. Figs, 2 and 3 show cross sectional views of the feed screw taken on the lines 22 and 3-3 ofFig..1.' t

WVhile I have shown, in the drawings and will describe fully herein, a preferred embodiment of my invention, it is apparent that it is susceptible of various modifications and altel-nativeconstructions and it should be understood thatI do not intend to limit the invention to the exact construction disclosed but aim to cover in the subjoined elaimsrall such modifications and alternative constructions falling within the scope of-the invention. My invention in general consists of three concentric cylindrical sleeves arranged in telescopic relation around :an angular-pin.

Theouter sleeveof the three is; fixed in the casing so as to preventany movement rela tive thereto. The inner sleeve constituting an inner feed member is slidable on an angular pin but is held against rotational movement.

The intermediate third sleeve constituting an.

outer feed member is disposed between the outer sleeve and inner feed member and is capable of both rotational and longitudinal movement. Aninterengaging relation between the three 'sleevesthrough the agency of right and left hand-screw threads'on the sleeves causes the inner sleeve to be propelled or projected outwardly and repelled or with,- drawn upon rotationof the intermediate sleeve. 5 I

; Referring to, thedrawings, I have showna casingl of a pneumatic, drill which" may be any general type, in which the telescopic feed screw 1s incorporated. The feed screw proects in part through an'opening 2 defined 1 t a flange 3 on the upper part of the casing 1- I and 1s arranged-ln'thecasing in axial, aline- I ment with a drill-carrying spindle 4Q The outer sleeve 5' of the feed screw, abuts the flange 3 at the top of the casing and the other end rests upon a ball bearing 6 in which thespmdle 4 turns. It is supported intermediate, the ends by'an upstanding wall 7 of theeasing'l and is rigidly secured in that position by being keyed as at 8 to the Wall 7 ofthe outer sleeve5', the sleeve isprovided with l-nternalright hand threads, the threads endlng at an internal abutment 9hav1nga central angular opening 10. Positioned within the outer sleeve 5 and in telescopic relation Throughout the major portion of the length her 11 is somewhat longerthanthe outer -sleeve 5 and extends through the opening 2 in the casing l fitting snugly therein;

Adja'cent the inner end, the outer feed member is externally enlargedjand threaded,

.these threads being the inter-engaging means.

between the outer sleeveand the outer feed member and being right hand in character. A

manually operable means for' imparting a rotational motion to the outerjfee'd member 7 is rigidly securedto the projecting end of' the member. This means is 'shown'here'as: a handle13 secured to the outer. feedm'em- *ber ll by' a'key 14; With the exception of the upper end portion of. the outer feed memher 11 to' which the handle is secured, the

outer feed member is internally left hand threaded throughout. Thus, upon rotation ofthe handle 13 on the outer feed memberll,

the member 11 will, because of its threaded relation with the sleeve 5, be projectedoutinner feed screwlQ is externally enlarged at its inner'end and is provided with left hand threads over the enlarged surface. The inner" feed member 1 2 hasL brOached the lower portion of its bore 1 an a gula opening 16 wardly from orwithdrawn into the sleeve 5' which is a continuation of the bore and which coincides with the angular opening 10 in the internal abutment 9 of the outer sleeve 5.

An extractor pin 17 having an angular cross section similar to the angular opening 10in the abutment 9'andthe opening 16 in the inner feed member 12 is" held therein .feedmember 11 is rotated by means of the handle 13, the inner feed member 12, being held slidably on the eXt-ractorpin 17 and havmg a threaded relation with the outer memvber 11, will be forced to travel through the outer member. The outer end of the inner feed member 12 is closed by a threaded bearing plug or feed sleeve center 18 which is used as a guide when placing the tool in operation.

The inner or lower end of the out-er sleeve 5 is counterbored as at 19 to receive abushing 20 for the spindle 4. The lower end of the angular extractor pin 17 is turned down cylindrically as shown in dotted lines at 21 and fits through a cylindrical bore in the spindle and is adapted to be forced into thetaper drill socket 22 to extract a drill therefrom. y

A stop means such as a pin 23 driven into .tlie 'e xtractor pin is adapted tolimit the longitudinal movement of the extractor pin by contact with the spindle d or the abutment 9 The feed screw as a unit is mounted in the casing in such a manner as to provide a fixed bearing for the spindle d and to be adirect longitudinal continuation of thespindle and subsequently the drill when the machine is operatin .Thus positioned, the drill, spindle and feed screw, form a unit extending through and perpendicular to a horizontal cross sectionalplane in the tool. i

The outer sleeve 5 of the feed screw, being keyed to the casing and being further held against displacen'ientby the flange?) and the ball bearing member 6 has no movement rela-j tive to the casingv The extractor pin 1'? extending through the angular opening 10 in the abutment 9 in the outer sleeve'is held against rotational movement the angular shape of the opening. 7 The extractor pin also having an angular engagementwvith the angular surface 16 broached in the; inner feed member prevents rotational movement of the inner member.

engagement with the outer sleeve 5 and a left hand threaded engagement with the inner feet to cause the inner-feed member to be pro- The intermediate or outer feed member 11 having a right hand threaded pelled outwardly, the handle 13 is rotated counter-clockwise. The outer feed member 11,being in right'hand threaded engagement with the stationary feed sleeve 5, will rotate and travel outwardly through the flange 3 in the casing. At the same time the inner feed member'12 being slidablymounted on the extractor pin 17 cannot rotate with the outer feed member 11 and having a left hand threaded engagement therewith is propelled outwardly through the outer feed member. Consequently, for every given distance traveled by the outer feed member 11 the inner feed member 12, being carried by the outer feed member and at the same time traveling through the outer feed member, will traverse approximately twice that distance. Thus, a multiplication of the movement imparted to the handle 13 is effected, producing a rapid operatingfeed.

The. simultaneousaction of the inner and outer feed members eliminates any chance of either member becoming entirely extended before the other begins to operate. As a result, each member acts to brace the other throughout the distance traveled.

The feed sleeve center-18 being rigid with the inner feed member, does not rotate, thus eliminating the, undue wear of this part which has heretofore been encountered.

for a pneumaticv only, manuallyoperated means on said secend sleeve to" impart rotational movement to sa d second sleeve, said three sleeves hav ng an interengaging.relatlon. whereby upon rotat-ion of said second. sleeve said third sleeve and said second sleeve will move longitudinally of the feed screw,

i 2. A pneumatic drillhaving, in combination, a casing, a telescopic feed screw mounted in saidcasing, sai lfeed screw comprising two concentrically arranged members, a single means engaging bothotsaid members to prevent relative rotation therebetween, and a third member positioned intermediate the first two members, said third intermediate member having a right hand threaded engagement with oncof said first two members i and having a left hand threaded engagement with the other member.

3. A pneumatlc'drill hav1ng,'1n comb nation, a casing, a telescopic feed screw secured in said casing and projecting therethrough, "said telescopic feed screw comprising three concentrically arranged sleeves, means rigfidly securing the outer sleeve 'to'said casing,

tion, a non-rotatably mounted-extractorpin,

a plurality of cylindrical relatively rotatable sleeves concentrically disposed about said pin and operable upon relative rotation to vary the total length of said feed screw, the inner sleeve being associated with said pin'so as to move longitudinally but non-rotatably on said pin. p y i 5. The combination with apneumatic drill having a vcasing and a rotatable spindle with a drill socket adapted torremovably receive a drill, of feeding means comprising three concentrically arranged sleeves mounted in said casing coaxially with said spindle, means securing one of said sleeves against longitudinal and rotational movement relative to said casin a in mounted within said sleeves for limited longitudinal movement to extracta drill from said socket, said pin engaging said fixed sleeve and one of said into an extended other sleeves to prevent relative rotation, and oppositely disposedthreaded means on the third one of said sleeves engaging said nonrotatable sleeves whereby said sleeves may be moved longitudinally of each other position by turning said rotatable sleeve.

6. In a pneumatic drill having a casing,

a rotatable spindlewith a drill socket therein adapted to removably receive a drill, the combination of feeding means comprising two concentric sleeves fixed. against rotation relative to each other and'relative to said casing, a third SlGGVBCOIlCGIltIlC with and rotatable relativeto said first two sleeves, said third sleeve having oppositely disposed threads engaging said other two sleeves whereby said sleeves may be moved longitudinally into extended-relation by rotating said third'sleeve, and an extractor pin mounted'within said sleeves and movable longitudinally thereof to extract a tool from said drill socket. a

In testimony whereof, I have hereunto af- GUSTAF SIGURD BRANTINGSON. 

